Extension device



April 4, 1939. scA MYRBERG EXTENSION DEVICE Filed Nov. 9, 1935 PatentedApr. 4, 1939 EXTENSION DEVICE Sven O. Myrberg, Providence, R. I.,assignor to Providence Stock Company, a corporation of Rhode IslandApplication November 9, 1935, Serial No. 49,083

6 Claims.

My present invention relates to the jewelry art, and has particularreference to extension devices for use with watch bracelets.

The invention has particular reference to eX- s tension devices of thepawl and ratchet type, and

has for its principal object the providing of means for positivelyopening the ratchet parts when the extension device is fully extended,and for positively locking the ratchet parts in co-operative relationwhen the extension device is closed.

A further object of the invention is to provide a simple arrangement ofparts which can be readily manufactured and easily assembled, and whichare particularly suitable for use with bracelets of narrow width.

With the above and other objects and advantageous features in View, theinvention consists of a novel arrangement of parts more fully disclosedin the detailed construction following, in conjunction with theaccompanying drawing, and more specifically defined in the claimsappended thereto.

In the drawing,

Fig. 1 is a plan View of the extension device, the parts being in closedrelation; y

Fig. 2 is a view similar to Fig. 1 but showing vthe length adjustmentlink in extended position;

Fig. 3 is a rear View of extension device of Fig. 1;

Fig. 4 is an enlarged section on the line 4 4 of Fig. 3;

Fig. 5 is a perspective view showing the extension device in openedposition;

Fig. 6 is a rear perspective View of Fig. 5;

Fig. 7 is a perspective View of the novel adjustment link; and

Fig. 8 is a perspective view of the novel spring pawl member.

Referring to the drawing, the novel extension device I includes a topmember I I having side flanges I2, I3, an intermediate member I4hingedly secured thereto, and preferably having side flanges I5, I6, abottom plate I8 having side flanges I l, I9, these side anges beingprovided with snap projections 2I, 22 for releasable locking. engagementwith the inturned edges of the anges I2 and I3, and a length adjustmentlink having an ear 24 for detachably receiving one end of a bracelet,the bottom plate I8 also having an ear .25 for receiving the other endof the bracelet.

As best shown in Figs. 2, and 6, the adjustment link 23 is slidablypositioned within the top member I I, and has side anges 25, 21 whichare housed within the side anges I2 and I3,

and a longitudinal slot 28, one side of which is provided with ratchetteeth 29. A spring pawl element 30, see Fig. 8, is provided with hingeears 3I, 32, which are mounted on the pivot pin 33, see Fig. 6, whichconnects the top member II f and the intermediate member I 4, the springpawl element 33 having a cross bar 30a and a spring pawl 34 whichterminates in an upwardly extending nger 35, the end of the pawl 33being displaced laterally so as to bring the finger 35 in adjacentsuperimposed relation to the ratchet teeth 29. The hinge ears 3I, 3.2are each provided with laterally extending tabs 33, 31, adapted to beengaged by the edges I5, I6 of the intermediate member when it is infully extended position; the intermediate member has a projection 38adapted to press downwardly on the bar 30a when the intermediate memberis moved to closed position.

The above described construction functions as follows: When the partsare in closed position, the projection 38 presses on the bar 33a, thuspressing the spring pawl member 35 upwardly and positively maintainingthe pawl nger 35 in rat'cheting relation to the ratchet teeth 29,whereby the adjustment link 23 may be moved inwardly toadjust the lengthof the extension device but cannot be moved outwardly to extend thesame. When the extension device is opened, the pawl and ratchet partsremain in engagement until the intermediate plate I4 is fully extended,the flanges I5, I6 then contacting the tabs 36, 3l and turning thespring pawl element 30 on the hinge pin 33 so as to lift the finger 35out of operative engagement with the teeth 29, whereby the pawl andratchet arrangement becomes inoperative, and the adjustment link 23freely moves outwardly to extend the open length of the extensiondevice. The pawl and ratchet parts again become operative when thehinged members are moved to closed position, thus permitting acontrolled inward movement of the adjustment link to obtain the desiredbracelet length. The teeth 29 may be cut to form setting recesses ifdesired, instead of ratchet teeth, the length adjustment then being madebefore the extension members are fully folded together.

The parts are preferably made of sheet metal, as the parts may bereadily stamped from this material; other suitable material such as wireor the like may be used, if desired, for any or all of the parts.

Although I have described a specific 'constructional embodiment of myinvention, and specific forms for the various parts thereof, any desiredchanges in the material used for the parts, in their shape, in theirrelative arrangements, and in their co-operating relationship, and anydesired re-arrangement of the parts to obtain extension devicesV havingdifferent numbers of foldable members, may be made to suit therequirements for different bracelet designs, without departing from thespirit` and the scope of -having a finger adapted to engage with saidratchet teeth, and a projection on said second member engageable withsaid pawl element to shift the finger into engagement with the ratchetteeth.

2. In an extension device,` a member, a second member hingedly connectedthereto and movable to open or to folded position with respect thereto,means for releasably locking said second member in folded relation tosaid first member, an adjustment link slidably secured to said firstmember and having ratchet teeth, a pawl element rotatably mounted insaid first member and having a finger adapted to engage With saidratchet teeth, and a lug on said pawl element engageable by said secondmember fo-r rotating said pawl element to shift the finger out ofengagement with the ratchet teeth. Y

3. In an extension device, a member, a second member hingedly connectedthereto and movable to open or to folded position with respect thereto,means for releasably locking said second member in folded relation tosaid rst member, an adjustment link slidably secured to said firstmember and having ratchet teeth, a pawl element rotatably mounted insaid first member and having a finger adapted to engage With'saidratchet teeth, a projection on saidV second member engageable with saidpawl element to shift the finger into engagement With the ratchet teeth,and a lug on said pawl element engageable by said second member forrotating said pawlV element to shift the finger out of engagement withthe ratchet teeth.

4. In 4an extension device, a member, a second member hngedly connectedthereto and movable to open or to folded position with respect thereto,means for Vreleasably locking said second member in folded relation tosaid first member, an adjustment link slidably secured to said rstmember and having recesses, a pawl element rotatably mounted Vin saidfirst member and having a fmger adapted tol engage With said recesses,and a projection on said second member engageable with saidpawl elementto shift the linger into engagement with the recesses.

5. In an extension device, a member, a second member hingedly connectedthereto and movable to open or to folded position with respect thereto,means for releasably locking saidv second member in folded relation tosaid first member, an adjustment link slidably secured to saidrst memberand having recesses, a pawl element rotatably mounted in said firstmember and having a finger adapted to engage with said-recesses, and alug o-n said pawl element engageable by said second member for rotatingsaid pawl element to shift the finger out of engagement with therecesses.

6. In an extension device, a member, a second member hingedly connectedthereto and movable to open or to folded position with respect thereto,means for releasably locking said second member in folded relation tosaid first member, an adjustment link slidably secured to said firstmember and having recesses, a pawl Yelement rotatably mounted in saidrst member and having a finger adapted to engage with said recesses, aprojection on said second member engageable with said pawl-element toshift the `nger into engagement with the recesses, and a lug on saidpawl element engageable by said second member for rotating said pawlelement to shift the nger out of engagement with the recesses.

SVEN o. MYRBERG.

